ABSTRACT
This chapter describes cryptosporidiosis in humans, specifically clinical manifestations, immunologic response to infection, putative patterns of transmission, and global epidemiology. The case of Cryptosporidium infection in a human was described in 1976 in a previously healthy 3-year-old child from a farm community in rural Tennessee. The child was vomiting and had severe watery diarrhea, malaise, and a dry cough, but recovered within 2 weeks; diagnosis of cryptosporidiosis was made by electron microscopic examination of rectal biopsy tissue. In 1982, the outbreak of cryptosporidiosis in immunologically healthy persons and the statistics from the Centres for Disease Control on cryptosporidiosis and acquired immunodeficiency syndrome were published. Cryptosporidium infects humans after oral ingestion of oocysts. Potential sources of organisms are other infected humans, animals, or the environment, particularly contaminated water. Cryptosporidium infection was recognized in humans because of its association with severe diarrhea; other clinical profiles including asymptomatic and extra-intestinal manifestations have received attention.
